Terminal deletion of the long arm of chromosome 10: A new case with breakpoint in q25.3

Since the first patient with partial deletion of the long arm of chromosome 10 was described in 1978, another 23 cases have been reported, with the breakpoint ranging from 10q23.3–26.2. To contribute further to the delineation of the monosomy 10qter syndrome, we describe a female child who, at age 3 6/12 years, was diagnosed with a de novo deletion of the long arm of chromosome 10, with a breakpoint in 10q25.3. The phenotypic manifestations in this child are compatible with those of previously reported cases. However, in contrast to most other patients, we found a moderate expression of the syndrome, with no genitourinary or cardiac malformations and with only mild retardation. Based on our observations and those of others, we conclude that a typical craniofacial appearance and varying degrees of psychomotor retardation are always found in patients with 10q− syndrome. Am. J. Med. Genet. 77:60–62, 1998. © 1998 Wiley-Liss, Inc.     

Proximal duplication of the long arm of chromosome 10 (10q11.2 → 10q22): a distinct clinical entity

This report summarizes the clinical and cytogenetic findings in a 16-year-old moderately mentally retarded girl with 10q11.2----10q22 duplication. The phenotypic findings are identical to those found in one other patient with the same autosomal duplication. These data suggest that proximal 10q11.2-10q22 duplication is associated with a specific clinically recognizable syndrome.     

Terminal deletion of the short arm of chromosome 5

Three cases of deletion of the short arm of chromosome 5 are described: one family cluster, in which the mother and three sons are affected, and two sporadics without the typical "cri du chat" phenotype (the family and Case 2 were previously reported in 1982). Mental retardation varied between affected members of the same family. Band p15.2 appears critical for the development of the complete phenotype. A peculiar deafness observed in the familial and one of the sporadic cases suggests a cochlear malformation.     

Delineation of subtelomeric deletion of the long arm of chromosome 6

Pure subtelomeric deletion of the long arm of chromosome 6 is rare. The frequency of this deletion accounts for approximately 0.05% of subjects with intellectual disability and developmental delay with or without dysmorphic features. Common phenotypes associated with this deletion include intellectual disability, developmental delay, dysmorphic features, seizure, hypotonia, microcephaly and hypoplasia of the corpus callosum. The smallest overlapped region is approximately 0.4 Mb, and contains three known genes. Of these genes, TBP has been considered as a plausible candidate gene for the phenotype in patients with a subtelomeric 6q deletion. Analysis of the breakpoints in 14 cases revealed a potential common breakpoint interval 8.0-9.0 Mb from the chromosome 6q terminus where the FRA6E fragile site exists and the PARK2 gene is located. This suggests that breakage at the FRA6E fragile site may be the mechanism behind chromosome 6q subtelomeric deletion in some of the cases.     

Terminal deletion of the short arm of chromosome 3

Summary A boy with growth and mental retardation, flat occiput, high and broad forehead, blepharoptosis, narrow palpebral fissures, low set, malformed ears, short neck, anal atresia, deep sacral dimple is reported. High-resolution banding analysis showed terminal deletion of the short arm of chromosome 3 (46,XY,del(3)(p25.3)). Deletions of the short arm of chromosome 3 are relatively rare. The clinical features of the patient are compared with those of 19 previously reported cases.     

Interstitial deletion of 10q: Clinical features and literature review

We report on a patient with interstitial deletion of 10q and compare her to 8 previously described patients, 2 of whom have chromosomal breakpoints similar to our patient. Minor anomalies including broad forehead, hypertelorism, strabismus, prominent philtrum, and “dysplastic” pinnae are present in our patient. Psychomotor retardation and hypotonia are universal findings in 10q interstitial deletion. Growth retardation, not present in our patient, is seen in some. These clinical findings are sufficiently distinct to suggest early chromosome studies. © 1992 Wiley-Liss, Inc.     

Mild phenotypic manifestations of terminal deletion of the long arm of chromosome 4: clinical description of a new patient

We present clinical and developmental data on a patient with a de novo terminal deletion of the long arm of chromosome 4. Cytogenetic studies after G-banding revealed the karyotype 46,XY,del(4)(q34). The 4-year-old male showed mild facial dysmorphism, moderate mental retardation with speech retardation, and marked deficits in gross motor skills. Our patient is the second with this deletion described in the literature. In both patients the phenotype was characterized by mild to moderate mental retardation, abnormalities of the pinnae, and nonspecific facial dysmorphism. The mild phenotype might explain why only two patients with this deletion have been described so far.     

Interstitial deletion of the short arm of chromosome 10: Report of a case and review of the literature

Summary The fifth patient with an interstitial deletion of the short arm of chromosome 10 is described. She showed most of the features observed in other known patients at age 20, including psychomotor retardation, distinct facial dysmorphism, abnormally shaped skull and cardiac malformation, while she did not show any growth retardation. The elevation of serum IgG level was observed from age 15, but she did not show DiGeorge syndrome. These differences would be explained by the differences in the amount of deleted segments using high resulution chromosome banding and molecular methods.     

Terminal deletion of the long arm of chromosome 4 in a mother and two sons

Deletion of chromosome 4q31→pter has been characterized as a distinctive malformation syndrome. We report a mother and two sons with deletion of the long arm (q) of chromosome 4 del(4)(q34.2).     

Clinical phenotype and molecular analysis of a three-generation family with an interstitial deletion of the short arm of chromosome 5

We report on a 3-generation family with an interstitial deletion of the short arm of chromosome 5. Varied manifestations were found among the affected individuals including microcephaly, hypertonia, and micrognathia; mental retardation was common to all affected individuals. High resolution chromosome analysis was interpreted as del(5) (pter->p14.3::p13.3->qter). Molecular comparison of the deletion in this family with individuals with other 5p deletions suggests that the clinical findings are due specifically to the chromosomal material deleted from 5p13. © Wiley-Liss, Inc.     

An interstitial deletion of the long arm of chromosome 13

A case of an interstitial deletion of chromosome 13, identified as 46,XY,del(13)(q22q31), is reported in a child with psychomotor retardation, prominent low-set ears, epicanthus, hypertelorism, broad nasal bridge, hypoplastic fifth fingers and abnormal dermatoglyphics. This patient is compared to others in the literature with a similar deletion.     

Smallest terminal deletion of the long arm of chromosome 2 in a mildly affected boy

We describe a male twin with the smallest terminal deletion of chromosome 2q [46,XY,del(2)(q37.2)] reported to date. His deletion was confirmed by a fluorescence in situ hybridization study using a probe from the deleted region. Only 3 other cases with larger deletions including 2q37.2→qter have been reported. Clinical manifestations our patient has in common with them include frontal bossing, long eyelashes, micrognathia, infantile hypotonia and developmental delay. His twin brother is physically and developmentally normal and chromosomes of the parents were normal. The mildness of the phenotype in this patient supports less stringent criteria for cytogenetic study of developmentally impaired individuals. © Wiley-Liss, Inc.     

Interstitial deletion of long arm of chromosome no. 5 with growth hormone deficiency-an emerging syndrome?

5p-is a well-defined syndrome, but phenotypic correlations of 5q are poorly described in the literature. We present a case of a female child with interstitial deletion in the 5q13.1q15 region. Comparison of the clinical features of this patient with others reported in the literature suggests an emerging clinical syndrome defined by short stature, failure to thrive, mental retardation, slanting palpebral fissures, malformed ears, short neck and depressed nasal bridge. Based on our endocrine testing, we hypothesize that the short stature could be, in part, due to growth hormone deficiency. The recent assignment of growth hormone receptor gene to the short arm of chromosome 5 and the presence of several genes for growth factors and growth factor receptors on 5q raise interesting possibilities for the explanation of short stature in such cases.     

Micromegakaryocytes in a patient with partial deletion of the long arm of chromosome 11 [del(11)(q24.2qter)] and chronic thrombocytopenic purpura

Thrombocytopenia or pancytopenia is frequently reported in patients with partial 11q deletion but there are no reports on bone marrow morphology of these patients. We report on a patient with partial deletion of the long arm of chromosome 11 [del(11) (q24.2qter)] and its classical clinical manifestations including chronic thrombocytopenic purpura in whom micromegakaryocytes were found in the bone marrow aspirate. This is the first report of the presence of micromegakaryocytes in the bone marrow of a patient with 11q deletion. Accurate examination of the bone marrow of other patients with the 11q deletion may clarify whether the observation of micromegakaryocytes is common in these patients. Micromegakaryocytes may indicate a defect of development. Two genes for two DNA binding proteins that are likely to be involved in hematopoiesis map in the 11q region: Ets-1, that maps to 11q24, close to D11S912, and the nuclear-factor-related-kB gene that maps to 11q24-q25. It is possible that these genes, when present in only one copy, result in thrombocytopenia or pancytopenia as observed in this patient. © 1996 Wiley-Liss, Inc.     

Loss of the N-myc oncogene in a patient with a small interstitial deletion of the short arm of chromosome 2

To our knowledge, only four previous cases of distal chromosome 2p deletions exist in the literature. We present a patient with minor facial anomalies who had a distal interstitial deletion of the short arm of chromosome 2, del(2)(p24.2p25.1). This patient had many features seen in other patients with distal 2p deletion including short stature, “rectangular” facies, microcephaly, hypotonia, and mental retardation. This patient also has sensorineural hearing loss which has been described in one other patient with a similar deletion. The N-myc oncogene has been mapped to 2p24. By fluorescence in situ hybridization using a cDNA probe for the N-myc oncogene, this patient was found to have a deletion of the N-myc oncogene. This confirms the previous map location for N-myc. © 1996 Wiley-Liss, Inc.     

Small terminal deletions of the long arm of chromosome 2: Two new cases

We report on 2 girls with small de novo terminal deletions of the long arm of chromosome 2 and breakpoints within q37. Four cases with similar or more extensive deletions have been previously reported in full. Hypotonia and psychomotor retardation were the only manifestations common to all 6 cases. The phenotype associated with small terminal 2q deletions is variable and clearly not always as mild as indicated in previous reports. The abnormality may also be more common than has been assumed. © 1994 Wiley-Liss, Inc.     

Two children with deletion of the long arm of chromosome 4 with breakpoint at band q33

A 10-year-old boy with developmental delay, craniofacial dy smorphia, malformations of the hands and feet and a cardiac malformation was found to have a small deletion of the distal region (q33 → qter) of the long arm of a chromosome 4. The clinical findings in this case are compared with those of a 17-week-old girl recently found to have the same deletion. Two additional patients with similar small deletions have been described in the literature. The similarity among the cases suggests the possibility of a deletion (4)(q33) syndrome. The major features of the syndrome are similar to those of larger deletions of the long arm of chromosome 4 and include mental and growth retardation, craniofacial dysmorphia including upslanting palpebral fissues, depressed nasal bridge, anteverted nares, abnormally shaped ears and micrognathia, and cardiac defects.     

A new syndrome of proximal deletion of the long arm of chromosome 1: 1q21–23→1q25

We present two unrelated children with the de novo interstitial deletion of the proximal segment of the long arm of chromosome 1 (1q21–23→1q25). Comparison of the phenotypic characteristics of these two patients with those of two previously described patients with similar deletion confirms the existence of the proximal 1q deletion syndrome. The characteristics of this newly recognized deletion syndrome include pre- and postnatal growth retardation; severe psychomotor retardation; microbrachycephaly; sparse, fine scalp hair and eyebrows; cleft lip and palate; hernias; genitalia defects; small hands and feet; and clinodactyly of the fifth fingers.